This invention relates to a pulse tube refrigerator/cryocooler apparatus and to a gas flow distribution device for use therewith.
The general function of a pulse tube cryocooler apparatus is well known to one skilled in the art, and generally includes the following features/components:    a) a piston for effecting cyclical movement of gas (e.g. Helium);    b) a regenerator for storing and recovering thermal energy of the gas moving cyclically in that direction as a result of the piston;    c) a pulse tube fluidly connected to the regenerator, acting as an insulator between the regenerator and the remainder of the cryocooler;    d) an inertance tube offering restriction and inertial effect to the cyclically moving gas, fluidly connected to the pulse tube; and    e) a container (often referred to as a “reservoir”) fluidly connected to the inertance tube, for storing a volume of gas.
The function of the cryocooler is to provide cooling to a device, particularly cryogenic temperatures. The present invention has been devised to achieve temperatures lower than 80K.
According to a first aspect of the present invention, we provide a pulse tube refrigerator/cryocooler apparatus including:    a) an inlet for receiving a cyclically moving volume of gas;    b) a regenerator device fluidly connected to the inlet for storing and recovering thermal energy from the gas;    c) a pulse tube fluidly connected to the regenerator; and    d) a conduit fluidly connected at one end to the pulse tube and fluidly connected at its opposite end to a container, said container providing a storage volume for gas,    e) wherein apparatus is configured such that the cyclically moving gas enters the regenerator in a direction parallel to its elongate axis.
According to a second aspect of the present invention, we provide a pulse tube refrigerator/cryocooler apparatus including:    a) an inlet for receiving a cyclically moving volume of gas;    b) a regenerator device fluidly connected to the inlet for storing and recovering thermal energy from the gas;    c) a pulse tube fluidly connected to the regenerator; and    d) a conduit fluidly connected at one end to the pulse tube and fluidly connected at its opposite end to a container, said container providing a storage volume for gas,    e) wherein the inlet is connected to the regenerator by a gas flow distribution device which distributes gas substantially evenly across and/or around the cross-sectional area of the regenerator.
According to a third aspect of the present invention, we provide a gas flow distribution device for use in a pulse tube refrigerator/cryocooler apparatus, including:    a) an inlet;    b) a plurality of outlets; and    c) a plurality of gas flow paths connecting the inlet to each of the outlets, wherein the length of the gas flow paths from the inlet to each respective outlet are substantially identical to each other.
Further features of the various aspects of the invention are set out in the claims attached hereto.